Russian President Vladimir Putin said Wednesday his troops have pulled back from the Ukrainian border — a claim immediately disputed by the White House — and also declared that an insurgent-backed referendum Sunday should be scrapped, raising questions about whether Mr. Putin has blinked or is merely trying to distance Moscow from further violence and unrest.

During a press conference with Swiss President Didier Burkhalter, Mr. Putin hinted that he was prepared to de-escalate the situation in eastern Ukraine by pulling back Russian forces.

He also welcomed talks with the government in Kiev, expressing support for Ukrainian elections May 25 and urging separatists to cancel plans for a vote Sunday on whether certain regions in eastern Ukraine should be granted more autonomy from the central government.

“We believe that the most important thing is to create direct, full-fledged dialogue between the Kiev authorities and representatives of southeast Ukraine,” he said. “Because of this, we ask that representatives of southeast Ukraine, supporters of federalization in the country, postpone the May 11 referendum in order to create the necessary conditions for such a dialogue.”

Within hours of Mr. Putin’s remarks, however, the White House and the Pentagon said there is no evidence Russian forces are pulling back. Leaders of the pro-Russia forces in eastern Ukraine, which have taken control of government buildings and other facilities and continue to foment unrest, also have given no indication that they will put the referendum on hold.

Some analysts say Mr. Putin is simply trying to stay one step ahead of the Obama administration. By disavowing Sunday’s referendum and appearing to back down militarily, the Russian leader may be able to distance himself from violence expected to break out this weekend if the vote goes forward, said Andrew Kuchins, director of the Russia and Eurasia Program at the Center for Strategic and International Studies.

“He’s brilliant. He’s put us on our heels a little bit,” Mr. Kuchins said. “People think this is a strategic shift by Putin. Is this de-escalation? I say 99.99 percent ‘no.’ But we have to wait and see. … No matter how weak his hand looks, he puts it to his favor.”

Mr. Putin made the remarks the same day that the White House took additional steps to punish Russia for its actions. President Obama announced that he would strip Russia of certain trade benefits and end the practice of taxing imported Russian goods at lower rates.

Last week, a round of economic sanctions aimed at crippling Russia’s economy was imposed in an effort to get Mr. Putin to change course. The administration has said it is prepared to move ahead with broader, sectoral sanctions.

The White House also said it would welcome the Russian president’s supposed actions but stressed that there is no proof.

“We could certainly welcome a meaningful and transparent withdrawal of Russian military forces, and that is something we have sought for some time,” Josh Earnest, White House principal deputy press secretary, told reporters Wednesday aboard Air Force One. “I will say that, to date, there has been no evidence that such a withdrawal has taken place.”

The Pentagon echoed those sentiments, as did NATO chief Anders Fogh Rasmussen, who told reporters he had “not seen any sign that Russia is withdrawing its troops.”

The continued presence of Russian troops on the Ukrainian border surely would stoke further tension ahead of Sunday’s vote. Ukrainian forces are continuing an offensive against pro-Russia activists, and at least 34 people have died as a result, according to the government in Kiev.

Further violence between rebels and Ukrainian troops in the city of Donetsk is feared over the weekend if the referendum is held.

The hastily arranged vote is scheduled to use paper ballots. Sidewalks in Donetsk have been spray-painted, with the word “referendum” appearing next to a scratched-out swastika, The Associated Press reported, demonstrating the insurgents’ claim that the new government in Kiev is fascist.

The referendum, as written, simply asks, “Do you support the act of proclamation of independent sovereignty for the Donetsk People’s Republic?”

Denis Pushilin, chief of the pro-Russia activists elections commission, said Wednesday he was confident that the vote would proceed.

“We are certain that people are fully familiar with the issues,” he said.

Despite Mr. Putin’s words Wednesday, the West’s efforts to de-escalate the situation through economic sanctions have had little impact and may have strengthened the Russian leader’s hand at home, Mr. Kuchins said.

“The Russian economy was already at zero growth. So now, as we sanction him, he flips that in his favor and says ‘our economy is suffering because of what the Europeans and Americans are doing.’ It works perfectly for his domestic political narrative,” he said.